I would recommend the free "Modern Embedded Systems Programming" video course on YouTube. The course starts from the beginning and is structured as a series of short, focused, hands-on lessons that teach you how to program ARM Cortex-M microcontrollers in C. The course now has grown to 20 lessons and it is headed to cover RTOS and other related concepts.

I would recommend the free "Modern Embedded Systems Programming" video course on YouTube. The course starts from the beginning and is structured as a series of short, focused, hands-on lessons that teach you how to program ARM Cortex-M microcontrollers in C. The course now has grown to 20 lessons and it is headed to cover RTOS and other related concepts.